1. Field of the Invention
This invention relates to a valve positioning handle and, more specifically, to such a handle which is designed to prevent the application of excessive forces to the valve during valve positioning which might cause damage or destruction to the valve or the piping in which it is installed.
2. Description of the Prior Art
There is an increasing demand for plastic valves to be utilized in association with plastic pipe in the gas distribution field. It is of continuing concern that these valves be designed to ensure that the system integrity will be maintained under adverse operating conditions. Federal operating standards, for example, require plastic pipe to be able to withstand pressures up to about 100 p.s.i. under operating temperatures ranging from 20.degree. F to +100.degree. F. Valves utilized with this pipe should satisfy similar requirements. Throughout this range of temperatures and pressures there is created a change in the characteristics of the plastic which complicates the basic problem of system reliability.
Specifically, it has been recognized that if the valve became jammed during efforts to open or close it, a situation could develop whereby a loss of system integrity might follow. Customarily, these valves are located underground and are operated by field service personnel with a variety of metal, torque applying tools. It is felt that if a valve became jammed, these rugged tools could be utilized to apply an excessive force to the isolation member and the body which could destroy the plastic valve or pipe. A crack or fracture in the isolation member, body or pipe could allow an uncontrolled escape of gas which would endanger personnel and property in the area.